This invention relates to a cover system for an open compartment. In particular, the invention relates to a cover system suitable for covering the open box, or cargo compartment, of a pick-up truck.
It is known in the art to provide a cover made of a flexible material and adapted to cover the box of a pick-up truck or the like, to protect the contents thereof from the elements. Such a cover can be made of fabric, flexible plastic, or other sheet material. The cover is commonly secured to a metal frame on the edge of the box with a method of reversible attachment. Because pick-up trucks typically are used and stored outdoors, the fabric and the means of attachment of the fabric to the frame are exposed to the elements which can include heavy moisture and extreme heat and cold, as well as dust, mud, rocks and other materials transported in the box.
The exposure to the elements creates problems for the covering and the structure used to reversibly attach the cover to the frame. Efforts to use convenient structures for attaching the cover to the metal structure tend to be subject to exposure to the elements and wear from repetitive use of the attachment means under those conditions. Moreover, exposure to heat and cold cause the covering to expand and contract, making the cover either loose and wrinkled in appearance, or making it difficult to secure the covering in the closed position.
A prior art attachment design for convenient reversible attachment of the covering to the frame uses a hook and loop fastening system sold under the trademark VELCRO®. In this system, strips of hook-bearing material are adhesively attached to a metal frame secured to the upper edges of the side of the truck box. Strips of loop-bearing material are permanently affixed to the downwardly facing surface of the cover material at its side edges opposite the metal frame. When the cover material is aligned over the truck box, and the strips of loop-bearing material on the downwardly facing side edges of the cover are pressed into contact with the strips of hook-bearing material adhesively fixed to the outer walls of the frame, such that a reversible yet secure mating is obtained. Although this system works well when first installed, it suffers from deterioration over time due to the repetitive pulling on the VELCRO® material attached to the frame in a direction away from the frame, particularly because it also is exposed to the elements. Specifically, the adhesive that attaches the hook-bearing strips to the frame will deteriorate over time because of the pulling motion which occurs when the cover is detached from the frame, and because of exposure to sun, moisture, and extreme temperature fluctuations. Moreover, heat or cold can cause the length and width dimensions of the cover and the frame to expand and contract, causing stresses in the adhesive bond of the VELCRO® material to the frame even when the cover is secured over the box.
Prior art cover systems employing the foregoing reversible attachment design also suffer from a problem associated with premature engagement of the hook and loop-bearing material attached to the frame and flexible cover, respectively. Premature engagement occurs in the prior art systems because as the user of the system unrolls the cover over the metal frame secured to the upper edges of the sides of a truck box or other open top container, the loop-bearing material attached to the downwardly facing surface of the cover material may engage the hook-bearing material attached to the metal frame at various points prior to the cover material being stretch taut. As a result, wrinkles may appear in the flexible cover material following closure of the cover system. To remove the wrinkles, the user is required to manually detach the strips of hook and loop-bearing material after the cover is stretched taut and then reattach them in a position that removes the wrinkles from the flexible cover.
It is thus one object of the invention to provide an attachment system for use with a cover for a truck box that provides a reversible yet secure attachment of the cover to the box, but will be resistant to deterioration as a result of repeated removal of the cover from the frame and exposure to the elements.
It is still another object of the invention to provide an attachment system for use with a cover for a truck box that provides an easily attachable and detachable covering without the prior art disadvantages of deterioration over time as a result of stresses applied during use.
In yet another aspect of the invention it is an object to provide a rail system for a cover system that minimizes, and preferably eliminates, the wrinkle problem associated with engagement of the fastening strips prior to the cover being fully closed and stretched taut.